Calcium is a basic element found in nearly all organized tissues. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It increases bone density and promotes the healthy development of teeth. Calcium is essential for the normal functioning of nerves and muscles. It is involved with normal muscle contraction, often helping to decrease muscle cramps. Calcium also plays a role in blood coagulation and in many enzymatic processes.
REQUIREMENT FOR HEALTHY BONES
Calcium is essential for the normal growth and maintenance of bones and teeth, and calcium requirements must be met throughout life. Requirements are greatest during periods of growth, such as childhood, during pregnancy and when breast-feeding. Long-term calcium deficiency can lead to osteoporosis, in which the bone deteriorates and there is an increased risk of fractures.
Osteoporosis remains a major health issue for more than 44 million Americans. Despite the fact that Americans consume more dairy products and calcium than any other population in the world, we still have one of the highest rates of this debilitating disease from calcium deficiency. One in two women and one in four men over age 50 will have an osteoporosis-related fracture in his or her lifetime. And while osteoporosis is often thought of as a disease of the elderly, it can strike at any age.
The foundation of strong and healthy bones is laid during childhood and the regular consumption of sodas impairs this process. Sodas contain phosphoric acid which leeches calcium from bones. Lack of regular weight-bearing exercise and dairy products during childhood also contributes to suboptimal bone formation during this time.
Calcium doesn’t work alone to build and maintain strong bones. Think of calcium as the bricks in the bone-building process. Bricklayers know a house is only as strong as the mortar that holds it together. And the nutritional mortar for building and maintaining strong bones includes vitamins D and K, magnesium, boron, zinc, copper and manganese. Vitamin D is necessary for adequate calcium absorption in the small intestine. Vitamin K helps to bind minerals together to form the bone matrix. Magnesium helps to incorporate calcium into bone and strengthen bones. Boron has been shown to aid in bone metabolism. Manganese, copper, and zinc are co-factors that activate enzymes that help build bone mass.
Calcium needs can be met by eating or drinking at least three or four servings of dairy products daily. Milk, yogurt, cheese and other dairy products are a prime source of calcium and are also fortified with vitamin D. Some dairy products, such as hard cheese and whole milk, do contain a significant amount of saturated fat, which can contribute to cardiovascular disease. Therefore, a diet consisting of low-fat dairy products should be considered. A low-fat variety of cheese made with part-skim milk, such as mozzarella, ricotta, cottage or farmer’s cheese might be chosen.
For those with an intolerance or allergy to dairy products, substitutes such as soya or rice milk often have calcium added to them. Calcium is the most abundant mineral in the body, but it is also the one most likely to be inadequately supplied in the diet. People who should especially consider supplementing their diet with calcium include women age 30 and older, teenagers, elderly and those who smoke, have high intakes of alcohol, or frequently drink soft drinks.
DIETARY CALCIUM SUPPLEMENTS
There are conflicting recommendations about when to take calcium supplements. However, most experts agree that no more than 500 mg should be taken at a time any excess will go to waste. It is recommended to spread doses throughout the day, with the last dose near bedtime. Recommended daily calcium intake varies from 1000 to 1500 milligrams, depending upon the stage of life. There are 4 different forms of calcium supplements.
1. Calcium carbonate is the most common and least expensive calcium supplement. It can be difficult to digest and causes gas in some people. Taking magnesium with it can help to prevent constipation. Calcium carbonate is 40% elemental calcium. 1000 mg will provide 400 mg of calcium. Take this supplement with food to aid in absorption.
2. Calcium citrate is more easily absorbed (bioavailability is 2.5 times higher than calcium carbonate), easier to digest and less likely to cause constipation and gas than calcium carbonate. It also has a lower risk of contributing to the formation of kidney stones. Calcium citrate is 21% elemental calcium. 1000 mg will provide 210 mg of calcium. It is more expensive than calcium carbonate and more of it must be taken to get the same amount of calcium.
3. Calcium phosphate costs more than calcium carbonate, but less than calcium citrate. It is easily absorbed and is less likely to cause constipation and gas than either.
4. Calcium lactate and calcium aspartate are both more easily digested, but more expensive than calcium carbonate.